Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b5e1a4e2869af5ffaa102535ad63d184d86e66ec
Commit: b5e1a4e2869af5ffaa102535ad63d184d86e66ec
Parent: b47711bfbcd4eb77ca61ef0162487b20e023ae55
Author: Aristeu Rozanski <[EMAIL PROTECTED]>
AuthorDate: Fri Jan 25 22:17:04 2008 +0100
Committer: Bartlomiej Zolnierkiewicz <[EMAIL PROTECTED]>
CommitDate: Fri Jan 25 22:17:04 2008 +0100
ide-io: set REQ_FAILED when drive is dead
Currently it's possible to ide-cd to set an incorrect blocksize by
reading garbage if the drive is dead:
ide_cd_probe()
-> cdrom_read_toc()
-> cdrom_read_capacity()
-> cdrom_queue_packet_command()
-> ide_do_drive_cmd()
-> ide_do_request()
-> start_request()
on start_request():
/* bail early if we've exceeded max_failures */
if (drive->max_failures && (drive->failures > drive->max_failures))
{
goto kill_rq;
}
(...)
kill_rq:
ide_kill_rq(drive, rq);
return ide_stopped;
ide_kill_rq() and the next calls won't set REQ_FAILED on rq->cmd_flags and
thus
cdrom_queue_packet_command() won't return an error. then:
stat = cdrom_queue_packet_command(drive, &req);
if (stat == 0) {
*capacity = 1 + be32_to_cpu(capbuf.lba);
*sectors_per_frame =
be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
}
cdrom_read_capacity() ends believing capbuf is valid but in fact it's just
uninitialized data. back to cdrom_read_toc():
/* Try to get the total cdrom capacity and sector size. */
stat = cdrom_read_capacity(drive, &toc->capacity,
§ors_per_frame,
sense);
if (stat)
toc->capacity = 0x1fffff;
set_capacity(info->disk, toc->capacity * sectors_per_frame);
/* Save a private copy of te TOC capacity for error handling */
drive->probed_capacity = toc->capacity * sectors_per_frame;
blk_queue_hardsect_size(drive->queue,
sectors_per_frame << SECTOR_BITS);
that will set drive->queue->hardsect_size to be the random value.
hardsect_size is used to calculate inode->i_blkbits. later on, on a read
path:
void create_empty_buffers(struct page *page,
unsigned long blocksize, unsigned long b_state)
{
struct buffer_head *bh, *head, *tail;
head = alloc_page_buffers(page, blocksize, 1);
bh = head;
do {
bh->b_state |= b_state;
tail = bh;
bh = bh->b_this_page;
} while (bh);
tail->b_this_page = head;
alloc_page_buffers() will return NULL if blocksize > 4096. blocksize is
calculed based on inode->i_blkbits. that will trigger a null
dereference on create_empty_buffers().
Signed-off-by: Aristeu Rozanski <[EMAIL PROTECTED]>
Cc: Borislav Petkov <[EMAIL PROTECTED]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[EMAIL PROTECTED]>
---
drivers/ide/ide-io.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index bef781f..bb1b0a8 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -1003,6 +1003,7 @@ static ide_startstop_t start_request (ide_drive_t *drive,
struct request *rq)
/* bail early if we've exceeded max_failures */
if (drive->max_failures && (drive->failures > drive->max_failures)) {
+ rq->cmd_flags |= REQ_FAILED;
goto kill_rq;
}
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
